SPRUIU1C July 2020 – February 2024 DRA821U , DRA821U-Q1
The PSILSS implements a PSI-L 1.2 interconnect between endpoints. Each endpoint connects to a CBASS that provides a CBA 4.0 VBUSP transport which is used to transport the PSI-L streams. The CBASS can implement any bridging needed for clock conversion, but any data width conversion is handled in the PSILSS as data width conversion in PSI-L requires special bridges for packing and unpacking data. In this context, a master endpoint is one that creates streams that go into the PSILSS, аnd a slave endpoint is one that consumes streams from the PSILSS and returns status.
The PSILSS converts the PSI-L signals to VBUSP signals in order to use the CBASS to perform the routing based on the thread maps and the requested destination thread. The CBASS performs the routing and switching of the traffic from a number of masters to a number of slaves. The masters send transactions to the CBASS. The CBASS decodes which slave is being accessed based on the signals and the map. The CBASS routes that transaction to the slave. The CBASS also arbitrates for a slave when there are multiple transactions being requested simultaneously, which can be based on transaction priority. Once a transaction is selected, the CBASS sends the transaction to the slave.